// SPDX-License-Identifier: GPL-2.0-only
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/******************************************************************************
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*******************************************************************************
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**
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** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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** Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
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**
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**
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*******************************************************************************
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******************************************************************************/
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/*
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* midcomms.c
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*
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* This is the appallingly named "mid-level" comms layer.
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*
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* Its purpose is to take packets from the "real" comms layer,
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* split them up into packets and pass them to the interested
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* part of the locking mechanism.
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*
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* It also takes messages from the locking layer, formats them
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* into packets and sends them to the comms layer.
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*/
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#include <asm/unaligned.h>
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#include "dlm_internal.h"
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#include "lowcomms.h"
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#include "config.h"
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#include "lock.h"
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#include "midcomms.h"
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/*
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* Called from the low-level comms layer to process a buffer of
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* commands.
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*/
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int dlm_process_incoming_buffer(int nodeid, unsigned char *buf, int len)
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{
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const unsigned char *ptr = buf;
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const struct dlm_header *hd;
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uint16_t msglen;
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int ret = 0;
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while (len >= sizeof(struct dlm_header)) {
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hd = (struct dlm_header *)ptr;
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/* no message should be more than this otherwise we
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* cannot deliver this message to upper layers
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*/
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msglen = get_unaligned_le16(&hd->h_length);
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if (msglen > DEFAULT_BUFFER_SIZE ||
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msglen < sizeof(struct dlm_header)) {
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log_print("received invalid length header: %u from node %d, will abort message parsing",
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msglen, nodeid);
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return -EBADMSG;
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}
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/* caller will take care that leftover
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* will be parsed next call with more data
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*/
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if (msglen > len)
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break;
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switch (hd->h_cmd) {
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case DLM_MSG:
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if (msglen < sizeof(struct dlm_message)) {
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log_print("dlm msg too small: %u, will skip this message",
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msglen);
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goto skip;
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}
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break;
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case DLM_RCOM:
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if (msglen < sizeof(struct dlm_rcom)) {
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log_print("dlm rcom msg too small: %u, will skip this message",
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msglen);
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goto skip;
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}
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break;
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default:
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log_print("unsupported h_cmd received: %u, will skip this message",
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hd->h_cmd);
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goto skip;
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}
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/* for aligned memory access, we just copy current message
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* to begin of the buffer which contains already parsed buffer
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* data and should provide align access for upper layers
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* because the start address of the buffer has a aligned
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* address. This memmove can be removed when the upperlayer
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* is capable of unaligned memory access.
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*/
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memmove(buf, ptr, msglen);
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dlm_receive_buffer((union dlm_packet *)buf, nodeid);
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skip:
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ret += msglen;
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len -= msglen;
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ptr += msglen;
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}
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return ret;
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}
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